Bosch Oven Error Code E118

E118 indicates a cooling fan supervision error in Cavity 1, the upper or single oven cavity. The control board has detected that the cooling fan speed is outside the acceptable range, either too low or too high. The fan speed is monitored by a Hall Effect Sensor that sends pulse signals back to the board. The fault can originate from the sensor connection, the wire harness, a misaligned plenum, or the fan motor itself.

It is generally not advisable to continue using the oven with an active E118 error. The cooling fan protects internal electronics and oven components from heat damage. If the fan is not operating at the correct speed, continued use risks overheating critical components, which could lead to more extensive and costly damage.

Repair costs depend on the root cause. If only a wiring harness reconnection or plenum realignment is needed, a service call fee of roughly $80 to $150 may cover the repair. Replacing the Hall Effect Sensor or fan motor typically adds $50 to $200 in parts, bringing total costs to a range of $150 to $400 or more depending on labor rates in your area and the specific parts required.

Some causes of E118 are accessible to a careful DIYer. Checking that the Hall Effect Sensor connector is fully seated and inspecting the wire harness for pinching or visible damage are reasonable first steps. However, accessing the cooling fan and plenum requires disassembling oven panels, and working near live electrical components carries risk. If you are not comfortable with appliance disassembly, a qualified technician is recommended.

A power reset, such as unplugging the oven or switching off the circuit breaker for a few minutes, may temporarily clear E118. However, if the underlying fault with the cooling fan, sensor, or wiring is still present, the error will return once the oven is operated again. A reset is useful for confirming whether the fault is persistent or intermittent, but it does not repair the root cause.